NPC2 and lysosomal storage disease: NPC1 and NPC2 are intracellular transporters that act in tandem to remove cholesterol from the lysosomal compartment37,39,56 and regulate cholesterol homeostasis through the generation of low-density lipoprotein cholesterol-derived oxysterols.56 Loss of function of NPC1 or NPC2 proteins is known to cause the lysosomal storage disease Niemann–Pick disease, type C1 and 2, respectively.37